An in-form Brendon McCullum will miss his team's push for the Caribbean Premier League Twenty20 title after suffering a bone fracture.

Former New Zealand captain McCullum was struck on his left forearm by South African paceman Wayne Parnell during his Trinbago Knight Riders' win over the Barbados Tridents yesterday.

X-rays confirmed serious damage, ruling the 35-year-old out for the rest of the season for the competition leaders.

The Knight Riders, who also boast Black Cap Colin Munro, finished the regular season with eight win from 10 games, ensuring they'll play in the first play-off game on Wednesday (NZT).

McCullum, who was on 26 when struck, is second in the CPL's run-scoring charts with 335.

He boasts the best strike rate (165.8) of any batsman among the top 10 run-scorers.

McCullum, a freelance T20 league player since retiring from the Black Caps last year, will hope to be fit to play for the Joburg Giants in the inaugural Twenty20 Global League starting in South Africa in two months.